超细晶Al-5Ti-xC的制备及对铝合金的细化机制

Preparation of ultrafine-grained Al-5Ti-xC and its refining mechanism on aluminum alloys

通过对Al-5Ti-xC进行快速凝固超细晶化处理以期更好的发挥其对铝合金组织孕育细化能力.将自制的Al-5Ti-xC细化剂在105~106℃/s的冷却速度下快速凝固,制备出宽约2 mm、厚约0.1 mm左右的薄带状产物.结果表明,经过快速凝固处理后的超细晶Al-5Ti-xC细化剂铸态组织中存在Al3Ti及TiC相,其中Al3Ti相得到很明显的细化,并且TiC更加弥散.向工业纯铝中加入2%的块状细化剂可以达到很好的细化效果,而加入0.5%的薄带状细化剂即可达到相同的细化效果.向ZL109中加入薄带状细化剂力学性能比加入块状细化剂有了较大的提高,硬度增加10%,高温拉伸强度增加11.4%.

To get a better refining capacity for Al alloys,the Al-5Ti-xC ribbon with the ultrafine grain was prepared by rapidly solidification,and the melt-spin ribbon with 2 mm in width and 0.1 mm in thickness were gained at a cooling rate of from 105℃/s to 106℃/s.The results show that,after rapid solidification processing,the structure as cast of ultrafinegrained Al-5Ti-xC refiner exists Al3Ti and TiC phases,in which Al3Ti phase is obviously refined,and TiC particles's distribution is more homogenously.The grains of commercial pure Al can be significantly refined after treated with 2% Al-5Ti-xC ingot,while adding 0.5% melt-spin ribbon,it can get the same grain size.Mechanical properties of ZL109 alloy refined by Al-5Ti-xC ribbons is better than that refined by ingot alloy,such as high temperature tensile strength and hardness are increased by 11.4% and 10%,respectively.